Railway signaling apparatus



Jan. 17, 1939. F. J. RYAN 2,144,432

RAILWAY SIGNALING APPARATUS I Filed Dec. 15, 1937 15 ATTORNEY Patented Jan. 17, 1939 PATENT OFFICE" I 2,144,432 RAILWAY SIGNALING APPARATUS Francis J. Ryan, Chicago, Ill., assignor to The Union Switch & Signal Company, Swissvalc, Pa., a corporation of Pennsylvania Application December 15, 1937, Serial No. 179,970

3 .Claims.

I My invention relates to'railway signaling apparatus, and particularly to control circuits for signals capable of displaying aplurality of indicatrolling'a plurality of indications displayed by each signal.

I shall describe one formv of apparatus embodying my invention, and shall then-point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters' a and b designate the rails of a stretch of railway track along which traffic may normally move in either direction. These rails are divided by insulated joints 5 to form a plurality of track sections IT, AlT and A2T. Undersome conditions, however, these three sections could be combined into one section, or could be divided into some other number of sections.

Each track section is provided with a track circuit including a source of current, shownas a battery 6, connected across the rails adjacent one end of the section, and a trackrelay, designated by the reference character R with a distinguishing prefix corresponding to the reference character for the associated track section, connected across the rails adjacent the other end of the section.

At one end of the stretch, asignal designated by the reference character I is shown for governing traiiic movements in a given direction into the stretch, and a signal designated by the reference character 4 is shown for governing trafiic movements in the opposite direction out of the stretch. At the opposite end of the stretch, a signal designated by the reference character 3 is shown for governing traflic movements in the givendirection out of the stretch, and a signal designated by the reference character Z is shown for governing traffic movements in the opposite direction into the stretch. As here shown, these signals are of the semaphore type, but they may be of any other suitable form. v A contact designated by the reference character 25 is shown as being operated in conjunction with signal 3, and is arranged tobe closed when signal 3 is displaying a proceed or caution indication for directing traffic movements out of the stretch, but to be open when signal 3 indicates stop. A similar contactdesignatedbythe reference character I6 is shown similarly operated in conjunction with signal 4.

A control relay is provided for each signal, designated by the reference character HR with a distinguishing numerical prefix corresponding to the reference character of the associated signal. A second control relay is shown for each of the signals l and 2, designated by the reference character DR with a distinguishing numerical prefix corresponding to the reference character of the 19 associated signal. Each HR relay controls a first indication of the associated signal, which may be the home or caution indication, and each DR relay controls a second indication of the associated signal, which may be the distant or proceed indi- 15. cation,

An asymmetric unit which may be of the wellknown copper oxide rectifier valve type, designated by the reference character 23, is included in the control circuit for relay IDR. This unit has 2 the characteristic that it permits current to flow through it freely in the direction indicated by the arrowhead portion of its symbol, that is, it has low resistance to current flowing in that direction, but obstructs the flow of current in the opposite direc- 25 tion, that is, it has high resistance to the flow of current in the opposite direction. A similar asymmetric unit, designated by the reference character i5, is included in the control circuit for relay 2DR.

As shown in the drawing, relay IHR is normally energized by a circuit passing from a given terminal of a source of current, here shown as a battery ll, through front contact l8 of relay 3H3, contact 19 of relay AZTR, conductor 20, contacts 3. 2| and 22 of relays AITR and ITR, respectively, winding of relay IHR, conductor l4, and return conductor 13 back to the opposite, terminal of battery ll. With relay IHR energized, a circuit, not shown, is closed for operating the arm of 40 signal I to the caution position, this circuit being similar to the circuit shown for signal 2 passing from a battery 26, through contact 21 of relay 2l-IR, mechanism of signal 2, and contact 29 of relay 2HR back to battery 26.

Relay IDR is energized by a circuitwhich includes the portion of the circuit traced for relay II-lZRpassing from battery I! through the contacts of relay 3I-IR and the track relays, and thence passing through asymmetric unit 23 in the .0 low resistance direction, winding'oi relay IDR, a

second return conductor 24, and contact 25 of signal 3, back to battery ll. With relay IDR energized, a circuit, not shown, is closed for operatingthe arm of signal 1 to the proceed position; 5.5;-

this circuit being similar to the circuit shown I shall now assume that, with the circuits for. relays IHR and IDR arranged as already described, the circuit for relay I l-lRjis closed from battery I! through conductor 20, but is open between conductor 20 and the winding of relay IHR, on account of contact?! of relay AlTR or contact 22 of relay ITR. being open, or on account of a broken conductor. I shall also assume that the circuit for relay IDR is open at contact of signal 3. If, under these conditions, there should be across between conductors-2i! and 24, asymmetric unit 23 would prevent false energization of relays lI-IR and ,IDR by current flowing from battery ll by way of the cross bet-ween conductorsZO-and 24. I

I shall next assume that the circuit for relay I HR is closed between contact [9 of relay AZTR and the winding of relay |HR,but that contact I 9 is open. I shall also assume that the circuit for relay IDR is closed. If, under these conditions, there should be a cross between conductors 2i] and 24, the two terminals of relay iI-IR, would be connected-to the same terminal of battery I1, and hence relay IHR would not-be falsely eneri It follows that the arrangement shown for circuits for controlling-two different indications of a signal, and an asymmetric unit placed as shown, provide eifective cross protection for such circuits.

By the accompanying drawing, my invention is shown applied to circuits for signals for governing trafiic movements in both directions along'a single track,:but it could also be similarly applied to circuitsfor signals for tracks over whichtra'mc movements normally are in one direction only, such-for example as the tracks of a double track line, one track Gf'WhiCh'l S usedfor tramc movements in a given direction and the other track of which is used for trafiic movements .in the V opposite direction.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scopeof the appended claims without departing from the spirit and scope ofmy invention.

Having thusdescribed my invention, what I claim is: l

.1. .In combination, a stretch of railway track includin'g oneor more track sections, a track circuit vfor each of said sections *eachfmcludin-g a track relay, a signal capable of indicating proceed or caution 'or stop for governing trafiic movements into said stretch :in a given direction, a second. signal capable .ofindi'cating stop o'rof displaying an indicationdirecting traffic movements out of :said stretch in said given direction,

a :contact operated by said. :secondsignal and openwhen said second signalindicates stop but closed'when said ,second signal is'displ'aying an indication for directing trafiic movements out of said; stretch aiprocee'd control'relay and a caution control relay for said :first signahan asymmetric unit; E ittin -3 W Q c r t na-g-iven dirction but obstructing fiow of current in the opposite direction, a circuit portion passing from a source of current through a front contact of each of said track relays, a circuit for energizing said caution control relay including said circuit portion and thence'passing through the winding of said caution control relay and by a return conductor to the opposite terminal of said source of current, a second circuit for energizing said proceed control relay including said circuit portion and thence passing through the winding of said proceed control relay in series with said asymmetric unit in said given direction and thence by a second return conductor through the contact operated by said second signal to the opposite terminal of said source of current, and means controlled by said caution and proceed control relays when energized for causing said first signal to indicate caution or proceed respectively.

2. In combination, a stretch of railway track, a signal capable of indicating proceed or caution orstop for governing traificmovements into said stretch, a first contact controlled by traffic conditions in said stretch closed when said stretch is unoccupied but open when said stretch is occupied, a second contact controlled by traffic conditions a givendistance in advance of said stretch closed when the track is unoccupied within said given distance but open when the track is occupied within said given distance, a proceed control relay and a caution control relay for said signal, an asymmetric :unit permitting flow of current in a given direction but obstructing flow of current in the opposite directioma circuit portion passing from a source of current through said first-contact, a circuit for energizing-said caution control relay. including vsaid circuit portion and thence passing through the winding of said caution control relay and back to the opposite'terminal of said sourceof current, a second circuit for energizing said ,proceed control relay including said circuit portion and thence .passing through the winding'of said proceed control relay in series with-said asymmetric unit in said given direction and throughysaid second contact back to said opposite terminal of-the source of current, and rrreanscontrolled by said caution and proceedcontrol relays-when 'energized'for causing said first signal-to indicate caution 'or proceed respectively, 5 "391m combination, a stretch of railway track, a si'gnal capable of displaying a-first or a second indication for directing traflic :movements :into said stretch, afirst and az-se'cond contact, means for separately "closing said-contacts, -a "first 'control relayand a second control rela'y for said signal an asymmetric-unit permittingfiow of current in a givendi-rection but "obstructing flow of current int'he'opposite direction, a circuit portion passing from-a source of current through said'firs't contact, a circuit-for energizing said first control relay including said circuit "portion and passing through the winding :of said first control relay-backto the opposite "terminal 'of said source or current, a second circuit for energizing said-second-control relay including said circuit portion and thence passing in said given direction through said "asymmetric unit and through-the winding of said second control relay and also, through said .second contac't'backto said 'oppositeiterminal of thesource of current, and

means controlled by said first .and second control f -rnANcrs I 

